20561683 has 2 divisors, whose sum is σ = 20561684. Its totient is φ = 20561682.

The previous prime is 20561663. The next prime is 20561689. The reversal of 20561683 is 38616502.

It is a strong prime.

It is a cyclic number.

It is not a de Polignac number, because 20561683 - 2⁹ = 20561171 is a prime.

It is not a weakly prime, because it can be changed into another prime (20561689) by changing a digit.

It is a polite number, since it can be written as a sum of consecutive naturals, namely, 10280841 + 10280842.

It is an arithmetic number, because the mean of its divisors is an integer number (10280842).

Almost surely, 2^20561683 is an apocalyptic number.

20561683 is a deficient number, since it is larger than the sum of its proper divisors (1).

20561683 is an equidigital number, since it uses as much as digits as its factorization.

20561683 is an odious number, because the sum of its binary digits is odd.

The product of its (nonzero) digits is 8640, while the sum is 31.

The square root of 20561683 is about 4534.4992005733. The cubic root of 20561683 is about 273.9594084469.

The spelling of 20561683 in words is "twenty million, five hundred sixty-one thousand, six hundred eighty-three".